


You Are My Greatest Sin

by babyboyplaid



Category: Supernatural
Genre: Age Play, Bottom Castiel, Daddy Kink, Deepthroating, Dubious Consent, Gaslighting, Guilty Castiel, M/M, Rough Oral Sex, Rough Sex, Top Dean, Underage Sex
Language: English
Status: Completed
Published: 2016-10-25
Updated: 2016-10-25
Packaged: 2018-08-24 14:04:13
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,999
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8374912
Author URL: https://archiveofourown.org/users/babyboyplaid/pseuds/babyboyplaid
Summary: Cas met Dean on an online chat room late one night. Now, he can't imagine life without him.





	

**Author's Note:**

> Please, please pay attention to the tags. They list out a few of the triggers in this fic. For clairty, this fic involves an underage (17) Castiel with an adult Dean. There is inherent dubious consent in this dynamic, not to mention how messed up consent is in the relationship anyways. There is implied abuse and there are some very rough moments in the fic. Please do not feel bad if you need to turn away from this fic. 
> 
> Other information: Dean is still a hunter but Cas is a human boy living in Oklahoma with a preacher for a father.

Cas’ phone vibrated in the pocket of his jeans, like a reminder of his guilt. He just kept his head bowed as his father continued to drone on with Grace, blessing the food they were about to consume. It wasn’t that Cas didn’t believe in God, it was just that he had different views that his devout father. It didn’t help that his father was also a preacher and took everything literally. With his phone vibrating in his pocket, he was reminded that what he was doing was quite possibly against everything his father wanted from his seventeen year old son. However, Cas couldn’t quite be bothered to care about that. Not when Dean was involved. 

Once Grace was said and Cas had managed to chew through a good chunk of his food, he excused himself and went off to his bedroom-- the exact place where Cas had met Dean. Well, not exactly. It was where Cas’ computer was and that was how he had met Dean. Late one night, Cas was hanging out in some chatroom for gay guys and soon enough, stumbled into Dean. 

Dean was exactly the enigma he needed in his life; he needed the man to get him through the dark and confusing angst of his teen years. Even though Dean was nearly twice Cas’ age, he figured that just meant that Dean had more experience and could help him get through his feelings. It was an added bonus that he had a really nice cock. When he got turned on, Cas could ignore the feelings in his gut; could ignore the guilt that was stirring deep in his soul. It was when the moment was over that he knew he would be left with the crash of his feelings; knew he would have to worry about his father finding out somehow that he was sleeping with a man, and an older one than that. 

As he made his way over to lay out on his bed, Cas pulled his phone out and smiled at the phone. Dean was drunk and he could tell that much. The words weren’t exactly spelled right but that just meant that Cas was going to have an even better time with Dean. They worked out the plans for their get together and Cas was practically giggling as he rolled out his plan. 

Dean was going to come and pick him up. 

As the night went on, Cas listened for the sound of his parents going to bed. Once he heard them close up into their room for the night, he hopped out of his bed and pranced over to his dresser. He was sure to quickly change into the baby blue briefs he kept stashed in the back of his underwear drawer. They were the ones that Dean had bought him and they were the man’s favorite. Which meant they were Cas’ favorite. He wiggled his perky little bottom into them and then pulled on his jeans and a tank top that would show off his midriff if he put his arms up into the air. It made him feel all kinds of ways to imagine Dean’s eyes on him; to imagine that he was wanted by Dean. That was an incredible moment for the teenage boy. And of course, his cock hardened with glee at what it meant when Dean wanted him. 

Soon enough, the time came and Cas opened his bedroom window and slipped out onto the ground below. He practically ran the length of the lawn out to the road and half a second later, that ever so familiar dark Impala drove up and Cas’ heart nearly jumped clean out of his chest. Dean was in there. 

He pranced around to the other side of the car and slid into the passenger seat. With that, they were off again. No time for people to be seeing this and such. Cas had a wide grin that stretched the span of his face and he raised himself up to place a small kiss on Dean’s cheek. 

“Missed you, old man.” He smirked with his lips still against the rough stubble of Dean’s face. 

“Missed you too, little brat.” There was a smile on Dean’s face. He could feel it. 

The words didn’t exactly come out perfectly pronounced and Cas could smell the whiskey rolling off Dean. But he didn’t mind. If anything, he wish he could have a glass with Dean right there in the car. Cas would do anything for the man, would do anything to see that approving look in his eyes. 

The tires rolled them up onto the interstate and Cas settled back into his seat, putting his feet up on the dash board. He got the distinct impression that Dean wouldn’t be one to normally allow that considering the man’s relationship with the car. But when you were cute as fuck and let the man bury his cock in your throat on the regular, you got special privileges. 

They chatted idly about how things were going. It was mainly Dean nodding as Cas went on and on about how much he couldn’t stand his life. How no one at school got him, how his parents drove him crazy. Dean would pipe in occasionally with some story from his life. In all honesty, he loved the tales of where Dean went in his life. He had some kind of job with the government that he wasn’t allowed to talk about, obviously. But it took him all over the place and Cas loved to hear the stories that he was allowed to hear about Dean’s travels. What he wouldn’t give to be on those travels with him. 

Eventually, they pulled up to a motel and that was another thing. Dean didn’t have a home. He just hotel hopped and when he was coming into Cas’ area, he would hit the boy up. It wasn’t that they stayed out of touch when Dean was on the road, it was just that they didn’t talk every minute of every day. They would exchange pleasent messages for periods of time and occasionally have a call here and there. Those mainly consisted of Cas whining and begging Dean to swing through Oklahoma. And he did, from time to time. 

They hopped out of the car and Cas took a look around. The parking lot was old and cracking and the sign seemed like it was hanging on its last hinge. But he was with Dean and that was all that mattered. Walking up to the room, it wasn’t as bad as Cas would’ve expected from the exterior. It was cozy enough. God, it smelled like Dean and it was all Cas could do not to bury himself in the sheets to soak up the smell; imprint it into his brain and carry it with him like a security blanket.  But of course he couldn’t. Plus, Dean had other ideas and in the moment, Cas liked those ideas better. 

As the door closed behind them, Dean’s fingers found their way into Cas’ hair and pushed Cas face first up against the wall. Dean was right there behind him though and Cas was just wiggling his bottom back into Dean’s crotch just to feel the swelling there. And god did it fill some deep seated need in Cas. 

“Gonna be a good boy for Daddy?” Dean growled, grinding up into Cas’ ass. 

“Gonna be the best.” Cas said, his breath nothing more than a breathy moan. 

That was perhaps the best known summary of their relationship: Daddy and boy. Dean was there to provide the structure and support, Cas was there to provide the entertainment and company and it all just worked out wonderfully. Sometimes, Cas went deeper into their dynamic than he was sure he should. Dean never said anything though; there was never a complaint from the older man when Cas did things like perch atop the end of a bed to watch cartoons or scribble silly little drawings into the backs of Dean’s notebooks. 

Dean’s hands were there exploring the inches of Cas’ skin, tracing familiar patterns and finding new ones to trace into Cas’ flesh. They stayed like that for a long moment, just grinding against the wall before Dean was ushering Cas further into the hotel. When they got next to the bed, Dean’s lips connected roughly with Cas’ and his little tank top was all but torn from his body a few minutes later. With that, Dean brought his lips down to Cas’ nipples and held the boy still as he began to torturous process of sucking on them. 

It was stimulation overload for Cas but Dean was just there, holding him still against the squirming as he sent overwhelming jolts of electricity through Cas’ body. He wanted to move away from the sensation but he’d promised his Daddy he would be good. Cas wasn’t as fond of Dean when Cas had managed to misbehave somehow. That was a side of his Daddy that he didn’t exactly like to draw out. 

And so that just leaves Cas standing there on the spot, squirming into his Daddy’s arms as the man has his way with him. It’s not that he doesn’t like it, it’s just too much for him to handle sometimes. It’s over soon enough and Cas knows he will be onto better things any moment. Dean manages to wiggle Cas out of his jeans and smirks approvingly when he sees Cas’ underwear choice. Dean just gives his rear a firm smack and Cas bites his lip, pressing a kiss to Dean’s cheek. 

“Wore them just for you, Daddy.”

“Such a good boy for me.” Dean practically purrs back. 

And when those words roll off of Dean’s tongue, they land like little ecstasy bombs all over Cas’ flesh and they travel deep into his gut to set into flight the butterflies he craves. Dean thinks he is a good boy and that is all that matters to Cas. All he needs to hear in life are those words. And when he looks up at Dean, his eyes are so full of admiration that he has to wonder why Dean coughs low and looks away. A second later though, Dean’s lips are rough on his neck and any thoughts in Cas’ head just go away. The man fills every inch of his brain. 

Slowly, Cas feels Dean urge him down onto his knees and he knows his prize is just about to come. Cas is instantly mouthing at the denim fabric that encases the man’s cock and Dean just lets out a slow growl. He keeps a firm grasp on Cas’ hair as he pulls his zipper down and lets it flop out. He doesn’t even unbutton his jeans and fuck if that isn’t turning Cas on even more. With that, Cas takes the head into his mouth and just lets it spread his jaws apart. He lets the musky saltiness fill up the space of his mouth and his whole world becomes about Dean’s cock. 

Eventually, he has worked his way up to moving his head up and down the shaft and Dean is just letting a slew of moans fall from his lips. It isn’t until Dean’s grip tightens in his hair that he knows he's in for the real treat. Dean forcefully pushes Cas all the way to the base of his cock and holds him there, constricting the boy’s airway. His world begins to blur as he gags on the obtrusive member in his throat but he doesn’t move away; he lets his Daddy hold him there until the man has decided it is time for Cas to move. When he is finally allowed off of Dean’s cock, he is coughing and spluttering and his hair has fallen to splay across his face. A sharp slap to the face brings him back into the moment and he suddenly remembers his protocol. 

“Th-thank you, D-Daddy.” He says in a shaky breath and god, that makes him slick the front of his briefs up even more. 

And then the cock is back in his mouth, gagging him once more. Cas is loving the way Dean roughly thrusts into his throat, using the boy’s dark hair as a gripping place to make sure he doesn’t get away. Not that Cas would move away anyways, but he is definitely loving the way it feels. His Daddy is in control of the moment and he would not have it any other way. 

Before he has a chance to process what is happening, he is being hoisted off the floor and thrown onto the bed. As he suspected, the sheets do smell of Dean and he buries his nose in them, drinking it up while he can. Dean yanks the briefs off of Cas’ legs and squats to spread the boy open. Cas lets out a shaky moan when he feels his Daddy’s hot breath on his sensitive hole and he knows what is coming. A second later, he feels the man’s tongue lapping at his entrance and his stubble is roughly rubbing into the sensitive flesh of his bottom. Cas bites the sheets in an attempt to muffle a cry but it is useless when Dean presses his tongue inside the boy. Cas’s head falls to the side and he lets out a lewd moan. There isn’t a favorite part of their ritual for Cas but this definitely ranks as one of the better moments. 

Dean takes his time to work Cas over and he has sunk into an abyss of ecstasy and moans. There is nothing but pleasure in the moment and that is all he needs. Dean knows how to treat Cas the right way and there aren’t words to express his gratitude for that. Dean is buried deep in Cas’ ass and Cas could not imagine a better feeling in the world. Soon, Dean takes a harsh bite on Cas’ bottom and he lets out a little squeak. When he hears Dean chuckle, he knows his Daddy is taking sadistic delight from this. There is a sharp slap to Cas’ bottom that follows shortly and he whimpers as he rolls onto the bed. 

Dean reaches down and grabs Cas’ by the head, dragging him up to look up at Dean. He places a finger below Cas’ chin and just keeps that devilish smirk on his face. 

“Who do you belong to, boy?” 

“You.” Cas says softly. 

“Who’s the only person that really cares about you?” 

“You.” Cas reiterates for Dean. 

A slap to his face sends Cas tumbling back onto the bed. “Don’t you forget it either.” 

Cas knows this is just what Dean likes during sex. He likes to play rough and Cas is more than ok with that. He watches with hazy eyes as Dean undresses and then he is there on top of Cas, pinning him to the mattress. His breath is hot on his cheek and he can smell the whiskey again. He almost can get a buzz off the smell alone. Or maybe it’s just Dean. 

Before he knows it, he is being turned over and his face is pressed into the pillow as Dean lines up his cock and lets it sink into Cas’ body. The only lube on it is Dean spitting a few times and it sends a fiery pain up into Cas’ body but he gets the impression that Dean just gets off on that as well. It isn’t long until Dean is letting out little grunts as he moves his cock in and out of Cas, fucking him without remorse. Dean couldn’t seem to care that Cas was in pain, just that he was getting pleasure out of the boy’s body. 

And somehow, that turns Cas on even more. 

Cas just bites down onto the pillow and he blushed fiercely as the voices of the boys from his school ring in his head. Pillow biter was an insult but in the moment, it was so true. Dean pounded away at Cas though and he just let his mouth move from the pillow, letting his cries of pain and pleasure fill the room. This elicited more pounding from Dean and before he knew it, he was coming against the sheets, making a mess between himself and the mattress. 

He could feel his hole clench around Dean’s cock and that earned a few deep growls from the man. He wasn’t finished though and the onslaught to Cas’ now sensitive hole continued. Cas just fell limply to the bed as his Daddy finished up from his end. He heard a few telling moans and then felt Dean’s hot come shooting out deep into him. 

Cas had done his job. He had made his Daddy happy. 

They laid in the quiet aftermath of the sex and Cas just blinked at the wall a few times. If his father knew that his son was getting fucked in some seedy hotel, he was sure the man would blow a gasket and die. Perhaps he should let his father in on the little secret. Soon enough, they got dressed and had to make the dreaded drive back to his place. Out on the road, Cas turned to Dean and gave him a sad little frown. 

“You be good, kiddo.” He tapped Cas’ chin with his finger. 

“I’m the best.” He smirked. 

With that, he was off across the lawn again. It wasn’t until he had climbed through his window and looked back that he saw Dean still sitting there. He wished he didn’t have to leave the man but now was not the time. He would be eighteen in a few months and maybe he could get Dean to let him run away with him then. Until then, all he could do was give a little wave and watch the red tail lights of that Impala fade off into the distance.   


**Author's Note:**

> Comments are love, my friends.


End file.
